chip in bathtub

I have a garden tub which was new when the house was built seven year ago. I noticed a small chip where the side meets the bottom, mostly on the side. What can I use to fill/repair this chip? It's not a deep gouge, more like a chip taken out of the finish.

The reason I asked is that I was in Lowes the other day and saw a white porcelain repair kit while I was looking for something to seal around the ends of my secondary HE tubes. Maybe I saw it to tell you. Who knows?

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